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How to Thin Flower Bulbs in Summer

By Jenny Harrington ; Updated September 21, 2017

Spring bulbs like daffodils, hyacinths and crocuses periodically need to be thinned, or divided, when they become overcrowded. Ovecrowded bulb gardens produce few blooms or fail to bloom entirely as the plants try to share too few nutrients in little space.

Daffodils need to be thinned every three to four years, while smaller bulbs like hyacinths and crocuses might not need to be thinned for five or more years. When thinning the beds, save healthy bulbs for new plantings or give them to other gardeners you know instead of tossing them.

Dig up bulbs eight weeks after all blooms have faded and as the foliage begins to yellow and die back. Dig around each plant to a depth of 6 to 8 inches and slide the spade under the bulbs and lift them out of the soil.

Brush away excess soil from each clump of bulbs. Rinse off lightly with water if the individual bulbs and where they join is difficult to see under the dirt.

Locate the joints between separate bulbs. Break apart bulbs where they join by gently twisting them apart.

Inspect bulbs for signs of damage, disease or soft spots that indicate rot. Discard any damaged bulbs and those that are small in comparison with the rest. Choose the largest bulbs for replanting.

Replant the bulbs in the bed to a depth three times the width of the bulb. Space larger bulbs, such as daffodils, 6 to 8 inches apart and space small bulbs, such as crocuses, 3 to 4 inches apart. Plant extra bulbs from the thinning in a new bed or give them away.


Things You Will Need

  • Spade


  • If you can't dig up the bulbs in early summer while foliage is still present, mark the location of the bulbs and dig them up later in the summer.
  • Work a teaspoon of bulb fertilizer into each hole before replanting to encourage healthy new root growth.
  • Store bulbs in a cool, dry place until fall if you can't replant right away or aren't sure yet where to plant extra bulbs.


  • Avoid digging up bulbs while they are still flowering, since this could damage them.
  • Use caution not to nick the bulbs with the spade as you dig them out.

About the Author


Jenny Harrington has been a freelance writer since 2006. Her published articles have appeared in various print and online publications. Previously, she owned her own business, selling handmade items online, wholesale and at crafts fairs. Harrington's specialties include small business information, crafting, decorating and gardening.